Enteral nutrition support and treatment toxicities in patients with head and neck cancer receiving definitive or adjuvant helical intensity-modulated radiotherapy with concurrent chemotherapy

BACKGROUND

Enteral nutrition (EN) is often required in patients with head and neck cancer (HNSCC); however, initiation criteria is limited or inconsistent. This study aimed to describe the relationship of treatment toxicities and requirement for EN and investigate toxicity and baseline characteristics association with EN duration.

METHODS

Acute toxicities and baseline characteristics were collected from patients with HNSCC (n = 110) undergoing H-IMRT. Percentage EN contributing to estimated requirements and EN duration were measured.

RESULTS

The threshold for patients needing ≥50% of estimated requirements via EN increased from week 3 to 4 for grade ≥2 oral/pharyngeal mucositis, dysgeusia, thick saliva and nausea, and for grade 3 dysphagia. Patients with grade 2-3 dysphagia had a reduced risk of ceasing EN compared to those with grade 0-1 dysphagia.

CONCLUSIONS

Using acute toxicities in clinical practice may be a useful tool to inform prompt initiation of EN prior to decline in nutritional status and anticipate EN duration.

Improving patient and carer access to information and support through head and neck cancer treatment and survivorship using experience-based co-design

BACKGROUND

Previous studies have highlighted the unmet nutritional and supportive care needs of patients with head and neck cancer (HNC) and their carers from diagnosis, and throughout the treatment and survivorship period. The aim of this study is to bring patients, carers and healthcare professionals together to co-design a framework to improve access to nutrition information and support for patients and carers with HNC from diagnosis and throughout the treatment and survivorship period.

METHODS

Using experience-based co-design (EBCD), semi-structured individual interviews were conducted with patients, carers and healthcare professionals to understand their experiences in accessing information and support outside of the hospital environment. Feedback events and co-design workshops were held to prioritise areas for service improvement.

RESULTS

Participants (10 patients, seven carers and 15 healthcare professionals) highlighted the importance of having consistent information and support recommendations from the multidisciplinary team. The two key areas for improvement identified through group and workshop events included linking reputable HNC resources to a HNC portal on the hospital website and the development of a series of short podcasts and video blogs with fact sheets attached presented by members of the multidisciplinary team, patients and carers at four time points spanning pre-treatment and throughout the survivorship period.

CONCLUSIONS

Using EBCD has enabled the co-design of a framework for resource development with patients, carers and healthcare professionals to improve access to information and resources to support nutrition intake and supportive care needs for patients with HNC with their carers. Development and implementation of resources and evaluation of outcomes is ongoing.

Acute high-intensity interval exercise attenuates incubation of craving for foods high in fat

OBJECTIVE

Food-seeking behaviors can be driven by food-associated cues, and palatable food seeking in response to food cues is a risk factor for obesity development. Cue-induced food seeking increases following a period of abstinence, a behavioral phenomenon known as "incubation of craving," which may contribute to an individual's difficulty abstaining from palatable foods. Pharmacological and environmental manipulations have been employed to try and reduce incubation of craving, albeit primarily in drug abuse paradigms. The goal of this study was to determine whether forced exercise can attenuate incubation of high-fat food craving.

METHODS

Male Sprague Dawley rats learned to self-administer high-fat pellets (60%) in combination with a compound cue (light + tone). The influence of high-intensity interval exercise on the time-dependent increase in cue-induced lever responding was investigated 30 days after the first cue test.

RESULTS

Rats exposed to exercise during abstinence did not express incubation of craving.

CONCLUSIONS

The results suggest that high-intensity exercise can prevent the establishment of incubation of craving for foods high in fat and may reduce cue-induced maladaptive food-seeking behaviors that contribute to overeating and obesity.

Tissue geometry drives deterministic organoid patterning

Epithelial organoids are stem cell–derived tissues that approximate aspects of real organs, and thus they have potential as powerful tools in basic and translational research. By definition, they self-organize, but the structures formed are often heterogeneous and irreproducible, which limits their use in the lab and clinic. We describe methodologies for spatially and temporally controlling organoid formation, thereby rendering a stochastic process more deterministic. Bioengineered stem cell microenvironments are used to specify the initial geometry of intestinal organoids, which in turn controls their patterning and crypt formation. We leveraged the reproducibility and predictability of the culture to identify the underlying mechanisms of epithelial patterning, which may contribute to reinforcing intestinal regionalization in vivo. By controlling organoid culture, we demonstrate how these structures can be used to answer questions not readily addressable with the standard, more variable, organoid models.

Patient and carer experience of nutrition care throughout and beyond treatment for head and neck cancer: a qualitative longitudinal study

Nutrition care plays a critical role in optimising outcomes for patients receiving treatment for head and neck cancer (HNC), with carers playing an important role in supporting patients to maintain nutrition intake. This study explores patient and carer experience of nutrition care from diagnosis of HNC to 1 year post treatment completion to identify areas for improvement of service delivery. A longitudinal qualitative study design was used with a heterogeneous sample of 20 patients and 15 carers of patients undergoing curative intent treatment for HNC. Interviews conducted at four time points provided a total of 117 interview datasets that were analysed using reflexive thematic analysis based on Gadamerian hermeneutic inquiry. Patient and carer experiences were reflected in two primary themes: (1) the battle to maintain control and (2) navigating the road ahead. This research identifies the need to co-design strategies to improve nutrition care that is inclusive of patients and carers.

Patients with HPV-associated oropharyngeal head and neck cancer have higher rates of weight loss and increased supportive needs

This editorial discusses the new evidence coming to light that patients with HPV‐associated head and neck cancer are at increased risk of nutritional decline during treatment, with increased weight loss and higher need for tube feeding. Due to the anticipated epidemic of this particular disease, there is an ongoing need for research to ensure nutrition care outcomes and supportive care needs are optimised in this sub group, which will improve clinical outcomes and enhance patient quality of life.

A method for evaluating cocaine-induced social preference in rats

Drug addicts are extremely sensitive to cues that predict drug availability and exposure to these cues can facilitate drug relapse. Cues vary in their nature but can include drug-associated paraphernalia, environmental contexts, and discrete conditioned stimuli (e.g., advertisements). One cue that has recently been heavily investigated is that of social interaction. To date, it has been demonstrated that when cocaine is conditioned with social interaction, place preference for cocaine significantly increases, suggesting that the presence of social interaction during a drug-associated “high” enhances the magnitude of drug reward. When social interaction is provided in a mutually exclusive, non-drug environment though, it can serve as a preventative stimulus towards cocaine seeking. What remains unknown is whether contact with rats associated with drug experience facilitates preferential social interactions for those rats. The first step in answering this question is to determine if rats can behaviorally discriminate between drug-associated and non-drug-associated conspecifics, much like humans can differentiate their “drug-friends” from their non-drug-using friends. Using a custom social interaction chamber, in which rats were able to interact with two distinct conspecifics via holes in a boundary wall, we demonstrate that rats exhibit more interactive and investigative behavior towards a partner that was consistently present during the drug-state, than a partner that was present when the rat was “sober”. It is our hope that this protocol will contribute to the development of models designed to study social cue-induced reinstatement, and related neural substrates, and will ultimately contribute to the treatment of substance use disorders.

Comparison of Nutritional and Clinical Outcomes in Patients with Head and Neck Cancer Undergoing Chemoradiotherapy Utilizing Prophylactic versus Reactive Nutrition Support Approaches

BACKGROUND

The optimal method of tube feeding for patients with head and neck cancer remains unclear. A validated protocol is available that identifies high-nutritional-risk patients who would benefit from prophylactic gastrostomy tube placement. Adherence to this protocol is ultimately determined by clinical team discretion or patient decision.

OBJECTIVE

The study aim was to compare outcomes after adherence and nonadherence to this validated protocol, thus comparing a prophylactic and reactive approach to nutrition support in this patient population.

DESIGN

We conducted a prospective comparative cohort study. Patients were observed during routine clinical practice over 2 years.

PARTICIPANTS/SETTING

Patients with head and neck cancer having curative-intent treatment between August 2012 and July 2014 at a tertiary hospital in Queensland, Australia, were included if assessed as high nutrition risk according to the validated protocol (n=130). Patients were grouped according to protocol adherence as to whether they received prophylactic gastrostomy (PEG) per protocol recommendation (prophylactic PEG group, n=69) or not (no PEG group, n=61).

MAIN OUTCOME MEASURES

Primary outcome was percentage weight change during treatment. Secondary outcomes were feeding tube use and hospital admissions.

STATISTICAL ANALYSIS PERFORMED

Fisher's exact, χ², and two sample t tests were performed to determine differences between the groups. Linear and logistic regression were used to examine weight loss and unplanned admissions, respectively.

RESULTS

Patients were 88% male, median age was 59 years, with predominantly stage IV oropharyngeal cancer receiving definitive chemoradiotherapy. Statistically significantly less weight loss in the prophylactic PEG group (7.0% vs 9.0%; P=0.048) and more unplanned admissions in the no PEG group (82% vs 75%; P=0.029). In the no PEG group, 26 patients (43%) required a feeding tube or had ≥10% weight loss.

CONCLUSIONS

Prophylactic gastrostomy improved nutrition outcomes and reduced unplanned hospital admissions. Additional investigation of characteristics of patients with minimal weight loss or feeding tube use could help refine and improve the protocol.

Measuring cellular forces using bis-aliphatic hydrazone crosslinked stress-relaxing hydrogels

Studies focused on understanding the role of matrix biophysical signals on cells, especially those when cells are encapsulated in hydrogels that are locally remodelled, are often complicated by appropriate methods to measure differences between the bulk and local material properties. From this perspective, stress-relaxing materials that allow long-term culture of embedded cells provide an opportunity to elucidate aspects of this biophysical signalling. In particular, rheological characterization of the stress relaxation properties allows one to link a bulk material measurement to local aspects of cellular functions by quantifying the corresponding cellular forces that must be applied locally. Here, embryonic stem cell-derived motor neurons were encapsulated in a well-characterized covalently adaptable bis-aliphatic hydrazone crosslinked PEG hydrogel, and neurite outgrowth was observed over time. Using fundamental physical relationships describing classical mechanics and viscoelastic materials, we calculated the forces and energies involved in neurite extension, the results of which provide insight to the role of biophysical cues on this process.

Validated swallowing and nutrition guidelines for patients with head and neck cancer: identification of high-risk patients for proactive gastrostomy

BACKGROUND

The "Swallowing and Nutrition Guidelines for Patients with Head and Neck Cancer" were developed to guide early identification and management of dysphagia and nutritional risk before, during, and after cancer treatment. The purpose of this study was to validate these guidelines.

METHODS

Patients attending a Combined Head and Neck Clinic at a major tertiary hospital in 2007 to 2008 were assessed using the guidelines, with high-risk category patients recommended for proactive gastrostomy. Data were collected on guideline adherence, gastrostomy tube insertion, and weight. Sensitivity, specificity, and positive predictive value were calculated for validation.

RESULTS

Proactive gastrostomy tubes were inserted in 173 of 501 patients (25%). Overall guideline adherence was 87%. High-risk category adherence was 75%. Validation outcomes were sensitivity 54%, specificity 93%, and positive predictive value 82%.

CONCLUSION

The risk categories in the guidelines are valid to assist early identification of swallowing and nutritional risk and guide decision-making on proactive gastrostomy tube insertion.

Component size asymmetry in bilateral total knee arthroplasty

A review of 268 consecutive patients undergoing bilateral total knee arthroplasty (TKA) was performed to determine whether component size asymmetry exists in patients undergoing bilateral TKAs. Component sizes were selected based on preoperative radiographic templating and intraoperative sizing measurements irrespective of the component sizes chosen for the other knee. All radiographs were evaluated according to described criteria. Component sizes used for the femur, tibia, and patella were compared between the right and left knees. Of the 268 bilateral TKAs, 18 (6.7%) femoral components varied in size between right and left knees. There were no statistical differences for patellar or tibial component size asymmetry or knee function pre- or postoperatively. Patients with asymmetrically sized femoral components had no statistical difference between left and right knees with respect to knee score, pain, function, range of motion, incidence of lateral release, or complications.

Attention deficit disorders and sleep/arousal disturbance

Many children, adolescents, and adults with Attention Deficit Disorders report chronic difficulties with falling asleep, awakening and/or maintaining adequate daytime alertness. These problems may be due to a variety of factors, including environment, lifestyle, and psychiatric comorbidities. Impairments in sleep/arousal may also be related more directly to the underlying pathophysiology of ADD. This chapter describes clinical manifestations of sleep/arousal problems often associated with ADD and reviews behavioral and medication options for treatment.

Orthostatic intolerance and motion sickness after parabolic flight

Because it is not clear that the induction of orthostatic intolerance in returning astronauts always requires prolonged exposure to microgravity, we investigated orthostatic tolerance and autonomic cardiovascular function in 16 healthy subjects before and after the brief micro- and hypergravity of parabolic flight. Concomitantly, we investigated the effect of parabolic flight-induced vomiting on orthostatic tolerance, R-wave-R-wave interval and arterial pressure power spectra, and carotid-cardiac baroreflex and Valsalva responses. After parabolic flight 1) 8 of 16 subjects could not tolerate 30 min of upright tilt (compared to 2 of 16 before flight); 2) 6 of 16 subjects vomited; 3) new intolerance to upright tilt was associated with exaggerated falls in total peripheral resistance, whereas vomiting was associated with increased R-wave-R-wave interval variability and carotid-cardiac baroreflex responsiveness; and 4) the proximate mode of new orthostatic failure differed in subjects who did and did not vomit, with vomiters experiencing comparatively isolated upright hypocapnia and cerebral vasoconstriction and nonvomiters experiencing signs and symptoms reminiscent of the clinical postural tachycardia syndrome. Results suggest, first, that syndromes of orthostatic intolerance resembling those developing after space flight can develop after a brief (i.e., 2-h) parabolic flight and, second, that recent vomiting can influence the results of tests of autonomic cardiovascular function commonly utilized in returning astronauts.

Cerebral vasoconstriction precedes orthostatic intolerance after parabolic flight

The effects of brief but repeated bouts of micro- and hypergravity on cerebrovascular responses to head-up tilt (HUT) were examined in 13 individuals after (compared to before) parabolic flight. Middle cerebral artery mean flow velocity (MCA MFV; transcranial Doppler ultrasound), eye level blood pressure (BP) and end tidal CO(2) (P(ET)CO(2)) were measured while supine and during 80 degrees HUT for 30 min or until presyncope. In the postflight tests subjects were classified as being orthostatically tolerant (OT) (n = 7) or intolerant (OI) (n = 6). BP was diminished with HUT in the OT group in both tests (p < 0.05) whereas postflight BP was not different from supine in the OI group. Postflight compared to preflight, the reduction in P(ET)CO(2) with HUT (p < 0.05) increased in both groups, although significantly so only in the OI group (p < 0.05). The OI group also had a significant decrease in supine MCA MFV postflight (p < 0.05) that was unaccompanied by a change in supine P(ET)CO(2). The decrease in MCA MFV that occurred during HUT in both groups preflight (p < 0.05) was accentuated only in the OI group postflight, particularly during the final 30 s of HUT (p < 0.05). However, this accentuated decrease in MCA MFV was not correlated to the greater decrease in P(ET)CO(2) during the same period (R = 0.20, p = 0.42). Although cerebral vascular resistance (CVR) also increased in the OI group during the last 30 s of HUT postflight (p < 0.05), the dynamic autoregulatory gain was not simultaneously changed. Therefore, we conclude that in the OI individuals, parabolic flight was associated with cerebral hypoperfusion following a paradoxical augmentation of CVR by a mechanism that was not related to changes in autoregulation nor strictly to changes in P(ET)CO(2).

Effect of parity on pituitary prolactin response to metoclopramide and domperidone: implications for the enhancement of lactation

OBJECTIVE

The gastrointestinal motility agents metoclopramide and domperidone are known to increase pituitary prolactin (PRL) secretion and breast milk production. This study compared the effect of single doses of two strengths of metoclopramide and a single dose of domperidone on PRL secretion.

METHODS

Ten nonpregnant women had baseline evaluation of serum PRL concentrations. The PRL concentrations were then determined after random oral administration of metoclopramide 10 mg, metoclopramide 5 mg, and domperidone 10 mg. Blood samples were drawn in the first 7 days of the menstrual cycle, at 13 time points over a 6-hour period (0, 15, 30, 45, 60, 75, 90, 120, 150, 180, 240, 300, and 360 minutes), with the zero time point beginning at 0800 hours. Variables such as weight, height, age, gravidity, parity, and oral contraceptive use were recorded.

RESULTS

Baseline PRL concentrations showed the natural circadian rhythm. Metoclopramide and domperidone both caused a significant increase in PRL. However, PRL secretion was most influenced by parity. Nulliparous women had the quickest and highest PRL secretion with metoclopramide 10 mg, compared with the PRL response with metoclopramide 5 mg and domperidone 10 mg. Conversely, multiparous women had PRL secretion patterns that were equivalent between the medications.

CONCLUSIONS

The PRL response to the medications was most influenced by parity. Therefore, we suggest that the medication therapy of choice for enhancing lactation may not be the same in all women, but may instead be determined by parity.

Dietary fat and calcium intakes of menopausal women

OBJECTIVE

The purpose of this retrospective, descriptive study was to assess the baseline dietary intake of fat and calcium in a group of women attending a multidisciplinary menopause clinic.

DESIGN

Dietary fat and calcium intakes of this group were determined with food-frequency questionnaires, food records, and dietary interviews. The dietary fat and calcium intakes of those patients who expressed concern of risk for cardiovascular disease or osteoporosis and those patients using herbal preparations were compared with those who did not.

RESULTS

Of 75 women, the majority of patients exceeded the dietary fat recommendations and had insufficient intakes of calcium. Significantly fewer patients with an expressed concern of risk for cardiovascular disease exceeded the recommendation for total fat and saturated fat (p < 0.05). There was no significant difference in calcium intake between those with and those without an expressed concern of risk for osteoporosis or in the diets of patients who did or those who did not take herbal products.

CONCLUSIONS

The large proportion of patients not meeting recommendations for fat or calcium intakes confirms that the assessment of baseline dietary habits and nutrition education and intervention should be an essential component of the management of menopausal women.

Cardiovascular and Valsalva responses during parabolic flight

We investigated the integrated cardiovascular responses of 15 human subjects to the acute gravitational changes (micro- and hypergravity portions) of parabolic flight. Measurements were made with subjects quietly seated and while subjects performed controlled Valsalva maneuvers. During quiet, seated, parabolic flight, mean arterial pressure increased during the transition into microgravity but decreased as microgravity was sustained. The decrease in mean arterial pressure was accompanied by immediate reflexive increases in heart rate but by absent (or later-than-expected) reflexive increases in total vascular resistance. Mean arterial pressure responses in Valsalva phases IIl, III, and IV were accentuated in hypergravity relative to microgravity (P < 0.01, P < 0.01, and P < 0. 05, respectively), but accentuations differed qualitatively and quantitatively from those induced by a supine-to-seated postural change in 1 G. This study is the first systematic evaluation of temporal and Valsalva-related changes in cardiovascular parameters during parabolic flight. Results suggest that arterial baroreflex control of vascular resistance may be modified by alterations of cardiopulmonary, vestibular, and/or other receptor activity.

Commun-I-Care: experience in the first four years

The medically uninsured ("working poor") comprise roughly 10 percent of the citizens in South Carolina. These individuals are more likely than the insured to have chronic health conditions including hypertension, diabetes, and respiratory diseases. They appear to have poorer outcomes as as result of misallocation of health care resources from prevention to acute intervention. CIC is a novel program which represents an effort to coordinate the efficient utilization of existing resources to meet the non-emergent health care needs of the medically uninsured. The CIC program has enjoyed a successful beginning and, with the continued strong support of providers and sponsors, looks forward to exciting progress in the future.

An episode of ventricular tachycardia during long-duration spaceflight

An episode of nonsustained ventricular tachycardia was recorded from a crew member during the second month aboard the MIR space station. Although asymptomatic, this cardiac event increases the concern that serious cardiac dysrhythmias may be a limiting factor during long-duration spaceflight.

Contributions of tidal lung inflation to human R-R interval and arterial pressure fluctuations

We studied the effects of mechanical lung inflation on respiratory frequency R-R interval and arterial pressure fluctuations in nine healthy young adults undergoing elective orthopedic surgery. We conducted this research to define the contribution of pulmonary and thoracic stretch receptor input to respiratory sinus arrhythmia. We compared fast Fourier transform spectral power during three modes of ventilation: (1) spontaneous, frequency-controlled (0.25 Hz) breathing, (2) intermittent positive pressure ventilation (0.25 Hz, with a tidal volume of 8 ml/kg) and (3) high frequency jet ventilation (5.0 Hz, 2.5 kg/cm2), after sedation and vecuronium paralysis. Mean R-R intervals, arterial pressures and arterial blood gas levels were comparable during all three breathing conditions. Respiratory frequency systolic pressure spectral power was comparable during spontaneous breathing and conventional mechanical ventilation, but was significantly reduced during high frequency jet ventilation (P < 0.05). Respiratory frequency R-R interval spectral power (used as an index of respiratory sinus arrhythmia) declined dramatically with sedation and muscle paralysis (P < 0.05), but was greater during conventional mechanical, than high frequency jet ventilation (P < 0.05). These results suggest that although phasic inputs from pulmonary and thoracic stretch receptors make a statistically significant contribution to respiratory sinus arrhythmia, that contribution is small.

Promethazine affects autonomic cardiovascular mechanisms minimally

Promethazine hydrochloride, Phenergan, is a phenothiazine derivative with antihistaminic (H1), sedative, antiemetic, anticholinergic, and antimotion sickness properties. These properties have made promethazine a candidate for use in environments such as microgravity, which provoke emesis and motion sickness. Recently, we evaluated carotid baroreceptor-cardiac reflex responses during two Space Shuttle missions 18 to 20 hr after the 50 mg intramuscular administration of promethazine. Because the effects of promethazine on autonomic cardiovascular mechanisms in general and baroreflex function in particular were not known, we were unable to exclude a possible influence of promethazine on our results. Our purpose was to determine the ground-based effects of promethazine on autonomic cardiovascular control. Because of promethazine's antihistaminic and anticholinergic properties, we expected that a 50-mg intramuscular injection of promethazine would affect sympathetically and vagally mediated cardiovascular mechanisms. Eight healthy young subjects, five men and three women, were studied at rest in recumbency. All reported drowsiness as a result of the promethazine injection; most also reported nervous excitation, dry mouth, and fatigue. Three subjects had significant reactions: two reported excessive anxiety and one reported dizziness. Measurements were performed immediately prior to injection and 3.1 +/- 0.1 and 19.5 +/- 0.4 hr postinjection. We found no significant effect of promethazine on resting mean R-R interval, arterial pressure, R-R interval power spectra, carotid baroreflex function, and venous plasma catecholamine levels.

Subnormal norepinephrine release relates to presyncope in astronauts after spaceflight

Postflight orthostatic intolerance is experienced by virtually all astronauts but differs greatly in degree of severity. We studied cardiovascular responses to upright posture in 40 astronauts before and after spaceflights lasting up to 16 days. We separated individuals according to their ability to remain standing without assistance for 10 min on landing day. Astronauts who could not remain standing on landing day had significantly smaller increases in plasma norepinephrine levels with standing than did those who could remain standing (105 +/- 41 vs. 340 +/- 62 pg/ml; P = 0.05). In addition, they had significantly lower standing peripheral vascular resistance (23 +/- 3 vs. 34 +/- 3 mmHg.1l-1).min; P = 0.02) and greater decreases in systolic (-28 +/- 4 vs. -11 +/- 3 mmHg; P = 0.002) and diastolic (-14 +/- 7 vs. 3 +/- 2 mmHg; P = 0.0003) pressures. The presyncopal group also had significantly lower supine (16 +/- 1 vs. 21 +/- 2 mmHg.1l-1).min; P = 0.04) and standing (23 +/- 2 vs. 32 +/- 2 mmHg.1l-1).min; P = 0.038) vascular resistance, supine (66 +/- 2 vs. 73 +/- 2 mmHg; P = 0.008) and standing (69 +/- 4 vs. 77 +/- 2 mmHg; P = 0.007) diastolic pressure, and supine (109 +/- 3 vs. 114 +/- 2 mmHg; P = 0.05) and standing (99 +/- 4 vs. 108 +/- 3 mmHg; P = 0.006) systolic pressures before flight. This is the first study to clearly document these differences among presyncopal and nonpresyncopal astronauts after spaceflight and also offer the possibility of preflight prediction of postflight susceptibility. These results clearly point to hypoadrenergic responsiveness, possibly centrally mediated, as a contributing factor in postflight orthostatic intolerance. They may provide insights into autonomic dysfunction in Earthbound patients.

Comparison of nifedipine alone and with diltiazem or verapamil in hypertension

Receptor binding studies suggest that combinations of calcium channel blockers may result in either enhanced or diminished pharmacological effects, but clinical data in hypertension are incomplete. In this study, we compared blood pressure reductions using nifedipine alone, nifedipine plus diltiazem, and nifedipine plus verapamil and determined whether combinations alter nifedipine pharmacokinetics. After determination of baseline blood pressures. 16 subjects with essential hypertension (12 men, 4 women; mean age, 48 years) received 30 mg/d open-label, sustained release nifedipine for 2 weeks. If still hypertensive (n = 16), they were randomized (double-blind) to receive either additional sustained release diltiazem or sustained release verapamil, both 180 mg/d, for 2 weeks and were then crossed-over for the final 2 weeks of the study. All medications were once-daily, extended-release formulations. Blood pressures and nifedipine plasma concentrations were measured during the final day of each treatment. Overall, each combination lowered mean systolic and diastolic pressures more than nifedipine alone. Mean supine diastolic pressures were significantly lower at 8 hours (77.6 versus 84.6 mm Hg, P = .001) and 12 hours (81.5 versus 87.1 mm Hg, P = .04) with nifedipine plus diltiazem than nifedipine plus verapamil. Mean nifedipine concentrations were inversely correlated with mean blood pressures. Mean nifedipine area under the curve values were greater with diltiazem than verapamil (1430 versus 1134 ng.h/mL, P = .026), with each greater than nifedipine alone (957 ng.h/mL). Nifedipine plus diltiazem had a greater antihypertensive effect than nifedipine plus verapamil. Diltiazem caused greater increases in nifedipine plasma concentrations than did verapamil. These data suggest that combined calcium channel blockers result in additive antihypertensive effects, perhaps because of a pharmacokinetic interaction.

'Non-hypotensive' hypovolaemia reduces ascending aortic dimensions in humans

1. The notion that small, 'non-hypotensive' reductions of effective blood volume alter neither arterial pressure nor arterial baroreceptor activity is pervasive in the experimental literature. We tested two hypotheses: (a) that minute arterial pressure and cardiac autonomic outflow changes during hypovolaemia induced by lower body suction in humans are masked by alterations in breathing, and (b) that evidence for arterial baroreflex engagement might be obtained from measurements of thoracic aorta dimensions. 2. In two studies, responses to graded lower body suction at 0 (control), 5, 10, 15, 20 and 40 mmHg were examined in twelve and ten healthy young men, respectively. In the first, arterial pressure (photoplethysmograph), R-R interval, and respiratory sinus arrhythmia amplitude (complex demodulation) were measured during uncontrolled and controlled breathing (constant breathing frequency and tidal volume). In the second, cross-sectional areas of the ascending thoracic aorta were calculated from nuclear magnetic resonance images. 3. Lower body suction with controlled breathing resulted in an increased arterial pulse pressure at mild levels (5-20 mmHg; ANOVA, P < 0.05) and a decreased arterial pulse pressure at moderate levels (40 mmHg; ANOVA, P < 0.05). Both R-R intervals and respiratory sinus arrhythmia were negatively related to lower body suction level, whether group averages (general linear regression, r > 0.92) or individual subjects (orthogonal polynomials, 12 of 12 subjects) were assessed. 4. Aortic pulse area decreased progressively and significantly during mild lower body suction, with 47% of the total decline occurring by 5 mmHg. 5. These results suggest that small reductions of effective blood volume reduce aortic baroreceptive areas and trigger haemodynamic adjustments which are so efficient that alterations in arterial pressure escape detection by conventional means.

Hypertension and endstage renal disease

OBJECTIVE

To review current literature regarding the development of hypertensive renal disease, its epidemiology, and its pathophysiology. This review focuses on strategies to slow or halt the progression of endstage renal disease (ESRD) in hypertension, including the role of blood pressure control, different types of antihypertensive agents, early treatment, and dietary considerations.

DATA SOURCES

Information was retrieved from searching the MEDLINE database for articles consisting of epidemiologic studies, clinical studies, and review articles pertaining to hypertension and ESRD. Information also was obtained from the US Renal Data System annual data reports.

STUDY SELECTION

Emphasis was placed on clinical trials in the English language addressing issues in hypertension and ESRD. Clinical trials reporting relationships between blood pressure control and ESRD, as well as those comparing different antihypertensive agents, were evaluated.

DATA EXTRACTION

The methodology and results from clinical trials were evaluated. Studies were assessed according to the measures of renal function used, baseline data collected, degree of blood pressure control, and antihypertensive therapy.

DATA SYNTHESIS

Clinical trials including patients with essential hypertension, diabetes mellitus, and renal insufficiency of various etiologies were evaluated. The recommendations from these evaluations were based on study design and the types of populations used (i.e., blacks vs. whites, diabetics vs. nondiabetics).

CONCLUSIONS

Blood pressure control is currently the most important strategy to slow or halt the progression of renal insufficiency in hypertensive individuals. Whether specific antihypertensives are renal protective is still controversial, but results from clinical trials are promising.

Human autonomic rhythms: vagal cardiac mechanisms in tetraplegic subjects

1. We studied eight young men (age range: 20-37 years) with chronic, clinically complete high cervical spinal cord injuries and ten age-matched healthy men to determine how interruption of connections between the central nervous system and spinal sympathetic motoneurones affects autonomic cardiovascular control. 2. Baseline diastolic pressures and R-R intervals (heart periods) were similar in the two groups. Slopes of R-R interval responses to brief neck pressure changes were significantly lower in tetraplegic than in healthy subjects, but slopes of R-R interval responses to steady-state arterial pressure reductions and increases were comparable. Plasma noradrenaline levels did not change significantly during steady-state arterial pressure reductions in tetraplegic patients, but rose sharply in healthy subjects. The range of arterial pressure and R-R interval responses to vasoactive drugs (nitroprusside and phenylephrine) was significantly greater in tetraplegic than healthy subjects. 3. Resting R-R interval spectral power at respiratory and low frequencies was similar in the two groups. During infusions of vasoactive drugs, low-frequency R-R interval spectral power was directly proportional to arterial pressure in tetraplegic patients, but was unrelated to arterial pressure in healthy subjects. Vagolytic doses of atropine nearly abolished both low- and respiratory-frequency R-R interval spectral power in both groups. 4. Our conclusions are as follows. First, since tetraplegic patients have significant levels of low-frequency arterial pressure and R-R interval spectral power, human Mayer arterial pressure waves may result from mechanisms that do not involve stimulation of spinal sympathetic motoneurones by brainstem neurones. Second, since in tetraplegic patients, low-frequency R-R interval spectral power is proportional to arterial pressure, it is likely to be mediated by a baroreflex mechanism. Third, since low-frequency R-R interval rhythms were nearly abolished by atropine in both tetraplegic and healthy subjects, these rhythms reflect in an important way rhythmic firing of vagal cardiac motoneurones.

Dance of the dialectic? some reflections (polemic and otherwise) on the present state of nineteenth-century asylum studies

The 1970s witnessed an intense, often acrimonious debate between revisionist and Whig/neo-Whig historians over the origins and nature of the nineteenth-century asylum experience. By the early 1980s, however, there had emerged no ""new synthesis" (as one might have expected given the dialectical nature of the historical enterprise) but rather a new counter-revisionist paradigm grounded in the precepts of the "new social history." This counter-revisionist paradigm has become, in turn, the "new orthodoxy" in asylum studies in the 1990s. This article argues that the counter-revisionist account is itself highly problematic, offering no convincing synthetic overview of the nineteenth-century asylum experience.

Important influence of respiration on human R-R interval power spectra is largely ignored

Frequency-domain analyses of R-R intervals are used widely to estimate levels of autonomic neural traffic to the human heart. Because respiration modulates autonomic activity, we determined for nine healthy subjects the influence of breathing frequency and tidal volume on R-R interval power spectra (fast-Fourier transform method). We also surveyed published literature to determine current practices in this burgeoning field of scientific inquiry. Supine subjects breathed at rates of 6, 7.5, 10, 15, 17.1, 20, and 24 breaths/min and with nominal tidal volumes of 1,000 and 1,500 ml. R-R interval power at respiratory and low (0.06-0.14 Hz) frequencies declined significantly as breathing frequency increased. R-R interval power at respiratory frequencies was significantly greater at a tidal volume of 1,500 than 1,000 ml. Neither breathing frequency nor tidal volume influenced average R-R intervals significantly. Our review of studies reporting human R-R interval power spectra showed that 51% of the studies controlled respiratory rate, 11% controlled tidal volume, and 11% controlled both respiratory rate and tidal volume. The major implications of our analyses are that breathing parameters strongly influence low-frequency as well as respiratory frequency R-R interval power spectra and that this influence is largely ignored in published research.

Fluoxetine and methylphenidate in combination for treatment of attention deficit disorder and comorbid depressive disorder

ABSTRACT Children and adolescents with attention deficit disorders (usually with comorbid conditions), who had shown inadequate therapeutic responses to methylphenidate, were treated by the addition of fluoxetine to methylphenidate. After 8 weeks in open trial, all 32 patients showed positive therapeutic responses in attention, behavior, and affect. Thirty of the 32 children showed clinically significant responses and the other two had statistically but not clinically significant responses. After 12 weeks of treatment, one patient showed a deterioration in clinical status. The children had improved report card grades in major academic subjects {p < 0.0001), and showed significant improvements (p < 0.0001) on the Children's Global Assessment Scale (C-GAS), Conners Parents Rating Scales (CPRS), and Children's Depression Inventory (CDI). Children who initially appeared more impaired on the C-GAS, CDI, CPRS, and GPA showed more improvement on the combined regimen. No significant side effects were observed, using a gradual elevation of fluoxetine dosage. About 40% of the patients showed substantial clinical effects with doses of fluoxetine below 20 mg daily. These preliminary results suggest that fluoxetine and methylphenidate in combination may be safe and effective for some children with attention-deficit hyperactivity disorder (and with comorbid anxiety or depressive symptoms) who do not show adequate responses to methylphenidate or fluoxetine alone.

Hydrostatic weighing without head submersion: description of a method

Hydrostatic weighing (HW) was performed at residual volume (RV) and total lung capacity without head submersion (TLCNS). Ninety-five males (25.6 +/- 4.9 yr) and 87 females (22.6 +/- 5.2 yr) were studied at two laboratory sites using identical protocols. Twenty males and 20 females were separated from the original group and randomly assigned to cross-validation groups. RVs were determined by the oxygen dilution method. Vital capacity was determined with the subject submerged in water to the shoulders. Underwater weight was determined using 10 trials at RV and 5 trials at TLCNS, with the order of methods randomly assigned. Regression analysis provided an equation to predict body density (pDb) at RV from body density (Db) at TLCNS. The equation for males was pDb (HW at RV) = 0.5829 (DbHW at TLCNS) + 0.4059, r = 0.88, SEE = 0.0067. The equation for females was pDb (HW at RV) = 0.4745 (DbHW at TLCNS) + 0.5173, r = 0.85, SEE = 0.0061. Cross-validation showed no significant differences using Db from HW at RV (males = 1.0626 g.ml-1, females = 1.0493 g.ml-1 and pDb from HW at TLCNS (males = 1.0625 g.ml-1, females = 1.0479 g.ml-1). The correlation coefficient SEE and total error for males were r = 0.95, 0.0043, and 0.0041, respectively and for females r = 0.82, 0.0084, and 0.0085, respectively. Mean percent fat for RV and TLCNS was identical for males and differed by 0.7% for females. Test-re-test data indicated the TLCNS procedure was reliable (r = 0.98).(ABSTRACT TRUNCATED AT 250 WORDS)

Anatomic staple closure of midline incision of the upper part of the abdomen

Using this technique of anatomic fascial staple closure, we have not seen a single wound disruption in nearly 800 patients. In the seven patients who had incisional hernias develop, all but one hernia occurred just above the umbilicus where the degree of fascial fiber dicussation was attenuated. In properly selected patients, our method of staple closure results in substantially decreased operating time and yields a dependable closure associated with minimal morbidity.

Foucault plus twenty: on writing the history of Canadian psychiatry in the 1980s

The untimely recent death of French philosopher-historian Michel Foucault, at the age of 57, serves as a sad reminder that twenty years have now passed since the publication in English translation of his seminal 1961 study Historie de la Folie. In the intervening years, and largely as a result of Foucault's provocative revisionism, the history of psychiatry has emerged as one of the most exciting and controversial growth areas of the “new social history”. Scholars, in both Europe and the United States, have begun a critical re-assessment of the history of “madhouses, mad-doctors and madmen” in post-Reformation Western society. In particular attention has focused on the origins and development of the lunatic asylum in the nineteenth century. Rejecting the long-held “Whig” explanation of the institution as one of the great nineteenth century “reforms”, revisionist historians have erected a new “social control” model in its place. Recently, however, this “new orthodoxy” of interpretation has itself come under attack as a second generation of asylum studies has begun to appear in print. Still confined, for the most part, to reviews and articles, this new work, less strident and dogmatic in tone than that of the “social control” historians, points to a more balanced and nuanced account of the nineteenth century asylum experience. Psychiatric history is once again in a state of flux and it seems highly unlikely that the decade of the 1980s will close without seeing the production of one or more new synthetic overviews of nineteenth century psychiatry to match those produced by David Rothman and Andrew Scull in the 1970s.

The origins of the asylum in Upper Canada, 1830-1839

Saturday, the 22nd of August, 1846 dawned “dull and unpromising” in Toronto. By the time the procession was ready to move off from old government house shortly after three o'clock in the afternoon, however, as the British Colonist recorded, “the sun's gladdening beams brightened all around.” Led by the band of the 81st Regiment, the large company slowly made its way out the Hamilton Road to the government military reserve. There, with a silver trowel presented by the building's architect, John G. Howard, Chief Justice John Beverley Robinson ceremoniously spread the mortar to set into place the “corner stone of the first building in Western Canada for the reception of Insane and Lunatic Persons.” Following an eloquent and heart-felt address by Robinson, the crowd, responding with enthusiasm, gave three cheers for the Chief Justice, the band struck up “Rule Britannia”, and the great gathering dispersed. The era of the asylum had officially begun in Upper Canada.

Natural killer cell function and lymphocyte subpopulation profiles in inflammatory bowel disease

Peripheral blood natural killer (NK) cell activity and lymphocyte subpopulation profiles were studied in 23 patients with inflammatory bowel disease (IBD) and in 16 healthy control subjects. NK activity was assessed by a 4-hr 51Cr release assay using K-562 erythroleukemia cell line targets. Both monocyte depleted and nondepleted lymphocyte preparations were tested using 50:1 and 25:1 effector to target cell ratios. Lymphocyte subpopulation profiles were determined by incubation of cell suspensions with the monoclonal anti-lymphocyte antibodies (OK-M1, OK-T4, Leu-4 and Leu-2) labeling with goat anti-mouse FITC and sorting by flow cytometry on the fluorescence-activated cell sorter (FACS). NK activity in patients with IBD showed wide variation, but mean activity was not significantly different from normal controls. Analysis of patient subgroups by disease activity, disease type, duration or treatment also failed to reveal significant differences from controls. Parallel measurements of peripheral blood lymphocyte subpopulations using these phenotypic markers revealed no significant differences between patients with IBD and control subjects.

The relationship between aerobic fitness and certain cardiovascular risk factors

Aerobic fitness and the incidence of risk factors related to cardiovascular disease (CVD) were compared for 2501 Canadian servicemen 18-50 years of age. Aerobic power (VO2max) was predicted from heart rate measured during submaximal bicycle exercise. The risk factors--serum cholesterol, serum triglycerides, blood pressure and body fat (sum of three skinfolds)--were measured; the incidence of cigarette smoking was obtained from a questionnaire. The total population tested was divided into three age groups which were subdivided into four fitness categories. An inverse relationship was demonstrated between fitness category and the mean values for all measured risk factors. Although this relationship was most evident in the older subjects, it is significant that it was also present in men under 30 years of age. A similar inverse relationship was demonstrated for all age groups between fitness category and the percent of subjects considered to have an elevated cholesterol, triglyceride, blood pressure, or skinfold thickness. The incidence of cigarette smoking was inversely related to fitness category only in those 30 years of age and over. Although this type of cross-sectional study does not establish cause and effect, there is evidence to suggest that participation in a program to improve physical fitness may lead the individual to modify other components of his lifestyle.

Psychotherapy in the residential treatment of the borderline child

The concept of borderline diagnosis is defined and the goals of residential treatment are delineated. The specific aims and techniques of psychotherapy are then outlined. Concomitant work with parents is utilized. The importance of working through during termination is noted.